Pabnell rabbidge



(No Model.)

P. RAB-BIDGE. TELBPHONIG INSTRUMENT.

No. 511,456. Patented Dec. 26, 1893;

me nunon. muoannvwua c'oMPAuv.

NITED STATES PATENT OFFICE.

PARNELL RABBIDGE, OF SYDNEY, NEW SOUTH VALES.

TELEPHONIC INSTRU M ENT.

SPECIFICATION forming part of Letters Patent No.- 511,456, dated December 26, 1893.

Application tiled April 22, 1893- Serial No. 471,479. (No model.)

instrument is hungon its hook the alarm orcall shall be in circuit, but when it is raised to the ear and mouth of` the speaker theA f transmitter and receiver shall be in circuit and the call will be cut out. They transmitter and receiver are connected together vin a manner somewhat similar tothat shown in my United States Patent No. 423,670, wherein when the receiver islplaced to the ear, the transmitter shall occupy a position opposite to the mouth of the speaker. The different circuits are controlled by a gravity switch that ,is placed within the arm by which the receiver and transmitter are connected together.

In the accompanying drawings:-Figure l is a vertical section of the whole apparatus. Fig. 2 is a plan view ot' the receiver with the ear piece and diaphragm removed. Fig. 3 is a plan view of the transmitter with the mouth piece and the diaphragm removed.

Fig. 4 is a cross section of Fig. 3, on the line 1-2. Fig. 5 is a back or under view of the plate that carries the microphone.

A, is a soft iron casting in the form of a shallow circular box.

B, is a brassrring 'screwed ontol the iron casting A, and which holds the ear piece C and diaphragm Cl of the receiver.

D, is a half ring of suitable insulating material for holding the terminals and vibrating armature in position.

E, is an electro magnet, the core E of which is rigidly secured to the casting A.

G, is the vibrating armature which is in the form of a fiat spring. It is the vibration of this armature that rapidly interrupts the current thus producing a rapid vibration of the receiver diaphragm and consequently giving out a musical note or sound which constitutes the call. The spring armature G, is carried by a brass .plate g, that is secured by the screw g,vand contact made with the casing A.

H, is a 4pillar that carries the adjustable Contact screw h, which is platinum tipped. This screw h,'rnakes contact with the spring armature G. In the receiver the diaphragm 'C, vmakes contact with the metal casing A, and thereby will form one pole of the elecrigidly secured a metal tube O, the extremity' of`which opens into the transmitter. The

transmitter consists ot' a hollow box P, the

form of which is shown in Figs. 1, 3 and 4.

Q, is a brass plate or cap that screws on the box P, and which holds the diaphragm q, in position. The mouthpiece R, is vsecured to the cap Q, which is provided with the usual central aperture to allow the sound waves to act on the diaphragm. g

Within the transmitter casing is secured a small slab S of slate or other suitable material. T-he slab S, forms a support for the microphone. The microphone consists of an indarubber or other suitable vflexible ring,

' the central space in which is filled with granular carbon. See transmitter in Fig. 1. The microphone is held in place between the diaphragm'q,and the slab S, by means of the screw T, which has its bearing in a brass plate t, which is secured to the slab S. They screw T, serves to regulate the degree of intimacy of contact between the granular carbon and the diaphragm. The contact sur faces of the diaphragm and the screw T, are platinized or otherwise suitably coated to prevent oxidation. u, is a screw plug, placed in the bottom of the casing P, and which may be removed for the purpose of adjusting the screw T. Within the hollow handle M, is placed a gravity switch V, which consists of a tubular vessel that contains a globule of mercury, and is provided with the necessary internal contact points for closing the different ICO through the gravity switch V, through Wire i 2, microphone S,diaphragm Q,case P, tube O, wire 3, case A, screw g', that is in contact with case A, electro magnet E, binding screw J, and to earth by wire 4. When the instrument is inverted the transmitter and receiver circuit will be cut out and the alarm circuit closed (see Fig. 2) from line wire through switch V, wire 5, binding screw J', contact screw h, screw g', electro magnet E, binding screw J, to earth through wire 4.

When the instrument is not in use ,it is hung upona hook by the curved portion of the tube 0,and will `therefore rbe 4in `the reverse ,position `to that `shown `in the drawings.

Having new particularly described and as certained the nature of my said invention and `in Whatmanner the samedis to be ipt n'formed, I declare that What I claim is- 1. In telephonie apparatus ythe telephone receiver with a spring armature `Contact breaker that is contained withinthe receiver casing whereby an linterrupted.current is obtained `and the diaphragm of the receiver is caused `to act as larralarnnor call; in ,combination with a transmtterthat is .rigidly Secured Ato the receiver by means of an arm, insuch a position that when the receiver isplaced to the `ear `the transmitter opposes `the mouthof the "operator, `as herein described.

2. In telephonie 4apparatus the telephone receiver `with a Spring rarmatlire Contact breaker that is contained withinthenreceiver casing whereby an interrupted currentis obtained alud tihediaphragm ,of lthe receiver is caused to act as an alarm or call; in combina tion with a transmitter that is rigidly secured to the receiver by means of an arm,in sncha position that when the receiver is placed to the ear the transmitter `opposes the mouth of the operator, and with a gravity switch which closes the required circuits according to the position in which the instrument is held as herein specified.

3. A receiver case, diapbragm,eiectro magnet and spring armature or contact breaker, the spring armature being distinct from the diaphragm and inclosed within the case, in combination `with Va gravity vswitch, whereby the alarm circuit shall be cutout when the receiver is held to the ear described,

"4. In telephonie apparatus a transmitter rigidly secured to a receiver insueh a position that when the `receiver `is placed to uthe ear the transmitterfis `opposite ,the ,mouth `0f? the Operate-r; .in combinati@ with gravity `switch whereby when the receiver isfplaccd to the tear the receiver and transmitter are both in circuit, andan lalarm o r call ,cut out of circuit vvhen the receiver nis placed to ,the

`ferrand `when the .instrument iS `placed in reversed 4pOSiiSOfl the `@infill .QF @all .is `00n- `nectedin circuit, and nthe receiverandtrans- `mittercut `out of circuit.

In witnesswhereef Ihav@ hereunto set my Yhand lin Ipresence of `tvvo Witnesses.

PARNELL Banshees.

Witnesses:

T. QRMOND 4OBrnmr, Notary BuZiaSydney, New Sou/th ilVctles.

Maserati) NEWTON, O'. 

